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Liang Y, Xu H, Tang W, Du X. The impact of metal implants on the dose and clinical outcome of radiotherapy (Review). Mol Clin Oncol 2024; 21:66. [PMID: 39091418 PMCID: PMC11289751 DOI: 10.3892/mco.2024.2764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 06/27/2024] [Indexed: 08/04/2024] Open
Abstract
Radiotherapy (RT) is one of the most widely used and effective cancer treatments. With the increasing need for organ reconstruction and advancements in material technology, an increasing number of patients with cancer have metallic implants. These implants can affect RT dosage and clinical outcomes, warranting careful consideration by oncologists. The present review discussed the mechanisms by which different types of metallic implants impact various stages of the RT process, examined methods to mitigate these effects during treatment, and discussed the clinical implications of metallic implants on RT outcomes. In summary, when metallic implants are present within the RT field, oncologists should carefully assess their impact on the treatment.
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Affiliation(s)
- Yuwen Liang
- Department of Oncology, Mianyang Central Hospital, Mianyang, Sichuan 621000, P.R. China
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637100, P.R. China
- Sichuan Clinical Research Center for Radiation and Therapy, Mianyang, Sichuan 621000, P.R. China
| | - Haonan Xu
- Department of Oncology, Mianyang Central Hospital, Mianyang, Sichuan 621000, P.R. China
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637100, P.R. China
- Sichuan Clinical Research Center for Radiation and Therapy, Mianyang, Sichuan 621000, P.R. China
| | - Wenqiang Tang
- Department of Oncology, Mianyang Central Hospital, Mianyang, Sichuan 621000, P.R. China
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637100, P.R. China
- Sichuan Clinical Research Center for Radiation and Therapy, Mianyang, Sichuan 621000, P.R. China
| | - Xiaobo Du
- Department of Oncology, Mianyang Central Hospital, Mianyang, Sichuan 621000, P.R. China
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637100, P.R. China
- Sichuan Clinical Research Center for Radiation and Therapy, Mianyang, Sichuan 621000, P.R. China
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2
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Henry M, Templeton A, Smith R. A low-cost phantom design for evaluating spine SABR calculations in the presence of prosthetic vertebral stabilization. Phys Eng Sci Med 2024; 47:1267-1276. [PMID: 38573488 DOI: 10.1007/s13246-024-01412-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 02/26/2024] [Indexed: 04/05/2024]
Abstract
Dose-perturbation characteristics are important to consider during the calculation of radiation therapy protocols for patients who are going to receive high doses that would reach the tolerance limits of the spinal cord [1]. Several studies have investigated dose perturbations introduced by metal implants in close proximity to spine SABR treatments [2-7]. However, there is a lack of work assessing this effect using the RayStation TPS [8]. We present an initial design for a low-cost phantom to evaluate spine stereotactic ablative radiotherapy (SABR) in the presence of prosthetic vertebral stabilization. The phantom is modular, allowing the prosthetic at the centre of the phantom to be removed by exchanging the central block. It also includes space to insert ion chamber and film. The agreement of the RayStation TPS (v8.0B) collapsed cone convolution (CCC) calculation and measurement was determined for phantom versions with and without prosthetic. There was little to no change in the agreement between the measured and calculated dose when introducing metallic hardware. This suggests that our Raystation-based SABR planning approach for patients with spinal hardware meets clinical expectations. Departments without access to anthropomorphic phantoms may find this design useful but should test their phantom design in typical clinical settings to ensure it is robust to real world situations.
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Affiliation(s)
- Michelle Henry
- Genesis Care - Fiona Stanley Hospital, Murdoch, WA, Australia.
| | | | - Ruth Smith
- Te Whatu Ora - Auckland City Hospital, Auckland, New Zealand
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3
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Ho D, Corde S, Chen C, Saade G, Betteridge C, Mobbs R. The use of carbon fiber/polyetheretherketone (CF/PEEK) in pedicle screw fixation for spinal neoplasms-potential advantages in postoperative imaging and radiotherapy planning. JOURNAL OF SPINE SURGERY (HONG KONG) 2024; 10:8-21. [PMID: 38567011 PMCID: PMC10982921 DOI: 10.21037/jss-23-93] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 02/08/2024] [Indexed: 04/04/2024]
Abstract
Background Titanium pedicle screw fixation complicates postoperative care in patients with spinal neoplasms due to postoperative imaging artefacts and dose perturbation. This study aims to measure the benefits of using carbon fiber/polyetheretherketone (CF/PEEK) pedicle fixation compared to titanium in postoperative imaging, radiotherapy planning and delivery for spinal neoplasms treated with conventional external beam radiotherapy with a commercial treatment planning system. Methods The properties of CF/PEEK pedicle fixation systems were compared to titanium in radiotherapy dose planning accuracy and postoperative computed tomography (CT) image quality. Dose profiles through the screw, tulip and longitudinal axis of the screw were acquired with radiochromic films and compared to a collapsed cone algorithm simulation, to measure dose agreement. The image quality of postoperative CTs were compared by defining four regions of interest around the vertebrae and screws in water phantom models and previous planning CTs, and comparing calculated artefact indexes (AIs). Results CF/PEEK screws have non-inferior dosimetric prediction accuracy up to 50 mm beneath the screw for collapsed-cone algorithm planning systems. There is a statistically significant reduction in the absolute difference between calculated and measured dose at a depth of 2 mm beneath the screw. There is minimal attenuation with CF/PEEK relative to the surrounding dose, extending to 50 mm beneath the screw. There is a statistically significant improvement in CT imaging quality with reduced AIs in CF/PEEK fixation compared to titanium in both model and patient CT plans. Conclusions CF/PEEK pedicle fixation can provide benefits in postoperative imaging and photon radiotherapy planning and delivery to patients with spinal neoplasms.
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Affiliation(s)
- Daniel Ho
- Faculty of Medicine, University of New South Wales, Sydney, Australia
- NeuroSpine Clinic, Prince of Wales Private Hospital, Randwick, Sydney, Australia
- NeuroSpine Surgery Research Group (NSURG), Sydney, Australia
| | - Stephanie Corde
- Department of Radiation Oncology, Prince of Wales Hospital, Randwick, SydneyAustralia
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Colin Chen
- Department of Radiation Oncology, Prince of Wales Hospital, Randwick, SydneyAustralia
| | - George Saade
- Department of Radiation Oncology, Prince of Wales Hospital, Randwick, SydneyAustralia
| | - Callum Betteridge
- Faculty of Medicine, University of New South Wales, Sydney, Australia
- NeuroSpine Clinic, Prince of Wales Private Hospital, Randwick, Sydney, Australia
- NeuroSpine Surgery Research Group (NSURG), Sydney, Australia
| | - Ralph Mobbs
- Faculty of Medicine, University of New South Wales, Sydney, Australia
- NeuroSpine Clinic, Prince of Wales Private Hospital, Randwick, Sydney, Australia
- NeuroSpine Surgery Research Group (NSURG), Sydney, Australia
- Department of Neurosurgery, Prince of Wales Hospital, Randwick, Sydney, Australia
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4
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Hirashima H, Nakamura M, Nakamura K, Matsuo Y, Mizowaki T. Dosimetric verification of four dose calculation algorithms for spine stereotactic body radiotherapy. JOURNAL OF RADIATION RESEARCH 2024; 65:109-118. [PMID: 37996097 PMCID: PMC10803157 DOI: 10.1093/jrr/rrad086] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/18/2023] [Accepted: 10/16/2023] [Indexed: 11/25/2023]
Abstract
The applications of Type B [anisotropic analytical algorithm (AAA) and collapsed cone (CC)] and Type C [Acuros XB (AXB) and photon Monte Carlo (PMC)] dose calculation algorithms in spine stereotactic body radiotherapy (SBRT) were evaluated. Water- and bone-equivalent phantoms were combined to evaluate the percentage depth dose and dose profile. Subsequently, 48 consecutive patients with clinical spine SBRT plans were evaluated. All treatment plans were created using AXB in Eclipse. The prescription dose was 24 Gy in two fractions at a 10 MV FFF on TrueBeam. The doses were then recalculated with AAA, CC and PMC while maintaining the AXB-calculated monitor units and beam arrangement. The dose index values obtained using the four dose calculation algorithms were then compared. The AXB and PMC dose distributions agreed with the bone-equivalent phantom measurements (within ±2.0%); the AAA and CC values were higher than those in the bone-equivalent phantom region. For the spine SBRT plans, PMC, AAA and CC were overestimated compared with AXB in terms of the near minimum and maximum doses of the target and organ at risk, respectively; the mean dose difference was within 4.2%, which is equivalent with within 1 Gy. The phantom study showed that the results from AXB and PMC agreed with the measurements within ±2.0%. However, the mean dose difference ranged from 0.5 to 1 Gy in the spine SBRT planning study when the dose calculation algorithms changed. Users should incorporate a clinical introduction that includes an awareness of these differences.
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Affiliation(s)
- Hideaki Hirashima
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Mitsuhiro Nakamura
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
- Department of Advanced Medical Physics, Graduate School of Medicine, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Kiyonao Nakamura
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Yukinori Matsuo
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Takashi Mizowaki
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
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Yadav P, Pankuch M, McCorkindale J, Mitra RK, Rouse L, Khelashvili G, Mittal BB, Das IJ. Dosimetric evaluation of high-Z inhomogeneity with modern algorithms: A collaborative study. Phys Med 2023; 112:102649. [PMID: 37544030 DOI: 10.1016/j.ejmp.2023.102649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/12/2023] [Accepted: 07/31/2023] [Indexed: 08/08/2023] Open
Abstract
PURPOSE To evaluate modern dose calculation algorithms with high-Z prosthetic devices used in radiation treatment. METHODS A bilateral hip prosthetic patient was selected to see the effect of modern algorithms from the commercial system for plan comparisons. The CT data with dose constraints were sent to various institutions for dose calculations. The dosimetric parameters, D98%, D90%, D50% and D2% were compared. A water phantom with an actual prosthetic device was used to measure the dose using a parallel plate ionization chamber. RESULTS Dosimetric variability in PTV coverage was significant (>10%) among various treatment planning algorithms. The comparison of PTV dosimetric parameters, D98%, D90%, D50% and D2% as well as organs at risk (OAR) have large discrepancies compared to our previous publication with older algorithms (https://doi.org/10.1016/j.ejmp.2022.02.007) but provides realistic dose distribution with better homogeneity index (HI). Backscatter and forward scatter attenuation of the prosthesis was measured showing differences <15.7% at the interface among various algorithms. CONCLUSIONS Modern algorithms dose distributions have improved greatly compared to older generation algorithms. However, there is still significant differences at high-Z-tissue interfaces compared to the measurements. To ensure accuracy, it's important to take precautions avoiding placing any prosthesis in the beam direction and using type C algorithms.
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Affiliation(s)
- Poonam Yadav
- Department of Radiation Oncology, Northwest Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Mark Pankuch
- Northwestern Medicine Chicago Proton Center, 4455 Weaver Parkway, Warrenville, IL 60555, USA
| | - John McCorkindale
- Department of Radiation and Cellular Oncology, Northwestern Medicine 1000 N Westmoreland Rd, Lake Forest, IL 60045, USA
| | - Raj K Mitra
- Department of Radiation Oncology, Ochsner Health System, New Orleans, LA 7012, USA
| | - Luther Rouse
- Philips Healthcare, 100 Park Ave, Beachwood, OH 44122, USA
| | - Gocha Khelashvili
- Department of Radiation Oncology, Northwest Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Bharat B Mittal
- Department of Radiation Oncology, Northwest Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Indra J Das
- Department of Radiation Oncology, Northwest Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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Paschal HMP, Kabat CN, Papaconstadopoulos P, Kirby NA, Myers PA, Wagner TD, Stathakis S. Monte Carlo modeling of the Elekta Versa HD and patient dose calculation with EGSnrc/BEAMnrc. J Appl Clin Med Phys 2022; 23:e13715. [PMID: 35985698 PMCID: PMC9512349 DOI: 10.1002/acm2.13715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 04/18/2022] [Accepted: 06/12/2022] [Indexed: 11/10/2022] Open
Abstract
Introduction Numerous studies have proven the Monte Carlo method to be an accurate means of dose calculation. Although there are several commercial Monte Carlo treatment planning systems (TPSs), some clinics may not have access to these resources. We present a method for routine, independent patient dose calculations from treatment plans generated in a commercial TPS with our own Monte Carlo model using free, open‐source software. Materials and methods A model of the Elekta Versa HD linear accelerator was developed using the EGSnrc codes. A MATLAB script was created to take clinical patient plans and convert the DICOM RTP files into a format usable by EGSnrc. Ten patients’ treatment plans were exported from the Monaco TPS to be recalculated using EGSnrc. Treatment simulations were done in BEAMnrc, and doses were calculated using Source 21 in DOSXYZnrc. Results were compared to patient plans calculated in the Monaco TPS and evaluated in Verisoft with a gamma criterion of 3%/2 mm. Results Our Monte Carlo model was validated within 1%/1‐mm accuracy of measured percent depth doses and profiles. Gamma passing rates ranged from 82.1% to 99.8%, with 7 out of 10 plans having a gamma pass rate over 95%. Lung and prostate patients showed the best agreement with doses calculated in Monaco. All statistical uncertainties in DOSXYZnrc were less than 3.0%. Conclusion A Monte Carlo model for routine patient dose calculation was successfully developed and tested. This model allows users to directly recalculate DICOM RP files containing patients’ plans that have been exported from a commercial TPS.
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Affiliation(s)
- Holly M Parenica Paschal
- Department of Radiation Oncology, School of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Christopher N Kabat
- Department of Radiation Oncology, School of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | | | - Neil A Kirby
- Department of Radiation Oncology, School of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Pamela A Myers
- Department of Radiation Oncology, School of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Timothy D Wagner
- Department of Radiation Oncology, School of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Sotirios Stathakis
- Department of Radiation Oncology, School of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
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Ab Shukor NS, Musarudin M, Abdullah R, Abd Aziz MZ. Monte Carlo simulation of HDR Brachytherapy dosimetric parameters in different mediums. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Pawałowski B, Ryczkowski A, Panek R, Sobocka-Kurdyk U, Graczyk K, Piotrowski T. Accuracy of the doses computed by the Eclipse treatment planning system near and inside metal elements. Sci Rep 2022; 12:5974. [PMID: 35396569 PMCID: PMC8993896 DOI: 10.1038/s41598-022-10072-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/25/2022] [Indexed: 11/09/2022] Open
Abstract
Metal artefacts degrade clinical image quality which decreases the confidence of using computed tomography (CT) for the delineation of key structures for treatment planning and leads to dose errors in affected areas. In this work, we investigated accuracy of doses computed by the Eclipse treatment planning system near and inside metallic elements for two different computation algorithms. An impact of CT metal artefact reduction methods on the resulting calculated doses has also been assessed. A water phantom including Gafchromic film and metal inserts was irradiated (max dose 5 Gy) using a 6 MV photon beam. Three materials were tested: titanium, alloy 600, and tungsten. The phantom CT images were obtained with the pseudo-monoenergetic reconstruction (PMR) and the iterative metal artefact reduction (iMAR). Image sets were used for dose calculation using an Eclipse treatment planning station (TPS). Monte Carlo (MC) simulations were used to predict the true dose distribution in the phantom allowing for comparison with doses measured by film and calculated by TPS. Measured and simulated percentage depth doses (PDDs) were not statistically different (p > 0.618). Regional differences were observed at edges of metallic objects (max 8% difference). However, PDDs simulated with and without film were statistically different (p < 0.002). PDDs calculated by the Acuros XB algorithm based on the dose-to-medium approach best matched the MC reference regardless of the CT reconstruction methods and inserts used (p > 0.078). PDDs obtained using other algorithms significantly differ from the MC values (p < 0.011). The Acuros XB algorithm with a dose-to-medium approach provides reliable dose calculation in all metal regions when using the Varian system. The inability of the AAA algorithm to model backscatter dose significantly limits its clinical application in the presence of metal. No significant impact on the dose calculation was found for a range of metal artefact reduction strategies.
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Affiliation(s)
- Bartosz Pawałowski
- Department of Medical Physics, Greater Poland Cancer Centre, Garbary 15, 61-866, Poznan, Poland.,Department of Technical Physics, Poznan University of Technology, Poznan, Poland
| | - Adam Ryczkowski
- Department of Medical Physics, Greater Poland Cancer Centre, Garbary 15, 61-866, Poznan, Poland.,Department of Electroradiology, Poznan University of Medical Sciences, Poznan, Poland
| | - Rafał Panek
- Medical Physics and Clinical Engineering, Nottingham University Hospitals NHS Trust, Nottingham, UK.,School of Medicine, University of Nottingham, Nottingham, UK
| | - Urszula Sobocka-Kurdyk
- Department of Medical Physics, Greater Poland Cancer Centre, Garbary 15, 61-866, Poznan, Poland.,Faculty of Health Sciences, Calisia University, Kalisz, Poland
| | - Kinga Graczyk
- Department of Medical Physics, Greater Poland Cancer Centre, Garbary 15, 61-866, Poznan, Poland
| | - Tomasz Piotrowski
- Department of Medical Physics, Greater Poland Cancer Centre, Garbary 15, 61-866, Poznan, Poland. .,Department of Electroradiology, Poznan University of Medical Sciences, Poznan, Poland.
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9
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Yadav P, Chang SX, Cheng CW, DesRosiers CM, Mitra RK, Das IJ. Dosimetric evaluation of high-Z inhomogeneity used for hip prosthesis: A multi-institutional collaborative study. Phys Med 2022; 95:148-155. [PMID: 35182937 DOI: 10.1016/j.ejmp.2022.02.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 02/04/2022] [Indexed: 01/27/2023] Open
Abstract
PURPOSE A multi-institutional investigation for dosimetric evaluation of high-Z hip prosthetic device in photon beam. METHODS A bilateral hip prosthetic case was chosen. An in-house phantom was built to replicate the human pelvis with two different prostheses. Dosimetric parameters: dose to the target and organs at risk (OARs) were compared for the clinical case generated by various treatment planning system (TPS) with varied algorithms. Single beam plans with different TPS for phantom using 6 MV and 15 MV photon beams with and without density correction were compared with measurement. RESULTS Wide variations in target and OAR dosimetry were recorded for different TPS. For clinical case ideal PTV coverage was noted for plans generated with Corvus and Prowess TPS only. However, none of the TPS were able to meet plan objective for the bladder. Good correlation was noticed for the measured and the Pinnacle TPS for corrected dose calculation at the interfaces as well as the dose ratio in elsewhere. On comparing measured and calculated dose, the difference across the TPS varied from -20% to 60% for 6 MV and 3% to 50% for the 15 MV, respectively. CONCLUSION Most TPS do not provide accurate dosimetry with high-Z prosthesis. It is important to check the TPS under extreme conditions of beams passing through the high-Z region. Metal artifact reduction algorithms may reduce the difference between the measured and calculated dose but still significant differences exist. Further studies are required to validate the calculational accuracy.
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Affiliation(s)
- Poonam Yadav
- Department of Radiation Oncology, Northwestern Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Sha X Chang
- Department of Radiation Oncology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Chee-Wai Cheng
- Department of Radiation Oncology, University Hospitals Cleveland Medical Center, Cleveland, OH 46255, USA
| | - Colleen M DesRosiers
- Department of Radiation Oncology, Indiana University Health, Indianapolis, IN 46202, USA
| | - Raj K Mitra
- Department of Radiation Oncology, Ochsner Health System, New Orleans, LA 70121, USA
| | - Indra J Das
- Department of Radiation Oncology, Northwestern Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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10
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Ab Shukor NS, Musarudin M, Abdullah R, Abd Aziz MZ. Monte Carlo Simulation of Hdr Brachytherapy Dosimetric Parameters in Different Mediums. SSRN ELECTRONIC JOURNAL 2022. [DOI: 10.2139/ssrn.4048875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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11
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To D, Xhaferllari I, Liu M, Liang J, Knill C, Nandalur S, Gustafson G, Lack D. Evaluation of VMAT Planning Strategies for Prostate Patients with Bilateral Hip Prosthesis. Technol Cancer Res Treat 2021; 20:15330338211038490. [PMID: 34490809 PMCID: PMC8427923 DOI: 10.1177/15330338211038490] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Purpose: In this study, we investigate linac volumetric-modulated arc therapy (VMAT) planning strategies for bilateral hip prostheses prostate patients with respect to plan quality and deliverability, while limiting entrance dose to the prostheses. Methods: Three VMAT plans were retrospectively created for 20 patients: (1) partial arcs (PA), (2) 2 full arcs optimized with 500 cGy max prostheses dose (MD), and (3) 2 full arcs optimized with max dose-volume histogram (DVH) constraint of 500 cGy to 10% prostheses volume (MDVH). PA techniques contained 6 PA with beam angles that avoid entering each prosthesis. For each patient, other than prostheses constraints, the same Pinnacle VMAT optimization objectives were used. Plans were normalized with PTV D95% = 79.2 Gy prescription dose. Organ-at-risk DVH metrics, monitor units (MUs), conformality, gradient, and homogeneity indices were evaluated for each plan. Mean entrance prosthesis dose was determined in Pinnacle by converting each arc into static beams and utilizing only control points traversing each prosthesis. Plan deliverability was evaluated with SunNuclear ArcCheck measurements (gamma criteria 3%/2 mm) on an Elekta machine. Results: MD and MDVH had similar dosimetric quality, both improved DVH metrics for rectum and bladder compared to PA. Plan complexities among all plans were similar (average MUs: 441-518). Conformality, homogeneity, and gradient indices were significantly improved in MD and MDVH versus PA (P < .001). Gamma pass rates for MD (99.0 ± 1.2%) and MDVH (99.2 ± 0.99%) were comparable. A significant difference over PA was observed (96.8 ± 1.6%, P < .001). Field-by-field analysis demonstrated 12/20 PA plans resulted in fields with pass rates <95% versus 1/20 plans for MD and none for MDVH. Cumulative mean entrance doses to each prosthesis were 62.9 ± 17.7 cGy for MD plans and 83.4 ± 27.5 cGy for MDVH plans. Conclusion: MD and MDVH plans had improved dosimetric quality and deliverability over PA plans with minimal entrance doses (∼1% of prescription) to each prosthesis and are an improved alternative for bilateral prostheses prostate patients.
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Affiliation(s)
- David To
- 7005Beaumont Health, Troy, MI, USA
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12
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Rojas DMC, Pavoni JF, Arruda GV, Baffa O. Gel and thermoluminescence dosimetry for dose verifications of a real anatomy simulated prostate conformal radiation treatment in the presence of metallic femoral prosthesis. J Appl Clin Med Phys 2021; 22:278-287. [PMID: 34436819 PMCID: PMC8504585 DOI: 10.1002/acm2.13403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 07/19/2021] [Accepted: 08/30/2021] [Indexed: 12/03/2022] Open
Abstract
This study aims to verify the dose delivery of prostate radiotherapy treatments in an adult pelvic phantom with two metallic hip and femur prosthesis using a four‐field box technique. The prostate planned target volume (PTV) tridimensional (3D) dose distribution was evaluated using gel dosimetry, and thermoluminescent dosimeters (TLD) were used for point‐dose measurements outside it. Both results were compared to the treatment planning system (TPS) dose calculation without using heterogeneity corrections to evaluate the influence of the metal in the dose distribution. MAGIC‐f gel dosimeter (Methacrylic and Ascorbic acid in Gelatin Initiated by Copper with Formaldehyde) associated with magnetic resonance imaging was used. TLD were positioned at several points at the bone metal interface and the sacrum region. The comparison of the gel measured and the TPS calculated dose distributions were done using gamma analysis (3%/3 mm), and a pass rate of 93% was achieved. The TLD dose values at the bone‐metal interface showed variations from the planned dose. However, at the sacrum region, where the beams did not intercept the prosthesis, there was a good agreement between TPS planning and TLD measurements. Our results show how the combination of 3D dosimetry and measurements at specific points in the phantom allowed a comprehensive view of the dose distribution and identified that care must also be paid to regions outside the PTV.
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Affiliation(s)
- Diana M C Rojas
- Department of Physics, Faculty of Philosophy, Sciences, and Letters, University of São Paulo, Ribeirão Preto, Sao Paulo, Brazil
| | - Juliana F Pavoni
- Department of Physics, Faculty of Philosophy, Sciences and Letters, University of São Paulo, Ribeirão Preto, Sao Paulo, Brazil
| | - Gustavo V Arruda
- Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Sao Paulo, Brazil
| | - Oswaldo Baffa
- Department of Physics, Faculty of Philosophy, Sciences and Letters, University of São Paulo, Ribeirão Preto, Sao Paulo, Brazil
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13
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Koutsouvelis N, Dipasquale G, Rouzaud M, Dubouloz A, Nouet P, Jaccard M, Miralbell R, Tsoutsou P, Zilli T. Bilateral metallic hip implants: Are avoidance sectors necessary for pelvic VMAT treatments? Z Med Phys 2021; 31:420-427. [PMID: 34210536 DOI: 10.1016/j.zemedi.2021.05.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 03/29/2021] [Accepted: 05/26/2021] [Indexed: 11/29/2022]
Abstract
PURPOSE Metallic hip implants (MHI) are common in elderly patients. For pelvic cancers radiotherapy, conventional approaches consist of MHI avoidance during treatment planning, which leads, especially in case of bilateral MHI, to a decreased quality or increased complexity of the treatment plan. The aim of this study is to investigate the necessity of using avoidance sectors (AvSe) using a 2-arcs coplanar pelvic volumetric modulated arc-therapy (VMAT) planning. METHODS We evaluated: (1) The dose calculation error of a static 6MV open beam traversing a MHI; (2) The magnitude of an error's decrease within the planning target volume (PTV) for a 360° VMAT treatment without AvSe as compared to the static open beam; (3) The dosimetric influence of MHI misalignment generated by patient's repositioning rolls during image-guided radiotherapy (IGRT). RESULTS (1) In the static 6MV beam configuration, for distances between 0.5cm and 6cm from the MHI, the median (maximum, number of points) dose calculation error was -1.55% (-2.5%, 11); (2) Compared to the static open beam, in the 360° VMAT treatment without AvSe a simulated error was decreased by a factor of 4.4/2.4 (median/minimum); (3) MHI anterior-posterior misalignment exceeding 0.6cm, resulted in error at PTV surface of >2%. CONCLUSIONS A standard 2 coplanar arcs 360° VMAT treatment, with dedicated artifact reduction algorithms applied, decreased the error of static beam traversing MHI, in patients presenting a bilateral MHI and might be used to treat the pelvic region without MHI avoidance.
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Affiliation(s)
| | - Giovanna Dipasquale
- Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland
| | - Michel Rouzaud
- Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland
| | - Angele Dubouloz
- Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland
| | - Philippe Nouet
- Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland
| | - Maud Jaccard
- Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland
| | - Raymond Miralbell
- Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland; Faculty of Medicine, Geneva University, Geneva, Switzerland
| | - Pelagia Tsoutsou
- Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland; Faculty of Medicine, Geneva University, Geneva, Switzerland
| | - Thomas Zilli
- Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland; Faculty of Medicine, Geneva University, Geneva, Switzerland
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Halvorsen PH, Hariharan N, Morelli ZT, Iftimia IN. Modeling of kyphoplasty cement for accurate dose calculations. J Appl Clin Med Phys 2021; 22:261-272. [PMID: 33599374 PMCID: PMC7984498 DOI: 10.1002/acm2.13174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 11/30/2020] [Accepted: 12/29/2020] [Indexed: 12/01/2022] Open
Abstract
We have determined the optimal method for modeling kyphoplasty cement to enable accurate dose calculations in the Eclipse treatment planning system (TPS). The cement studied (Medtronic Kyphon HV‐R®) consists of 30% Barium, 68% polymethylmethacrylate (PMMA), and 2% benzoyl peroxide, formulated to be radiopaque with kV imaging systems. Neither Barium nor PMMA have a high physical density, resulting in different interaction characteristics for megavoltage treatment beams compared to kV imaging systems. This can lead to significant calculation errors if density mapping is performed using a standard CT number to density curve. To properly characterize the cement for dose calculation, we 3D printed a hemi‐cylindrical container to fit adjacent to a micro‐chamber insert for an anthropomorphic phantom, and filled the container with Kyphon cement. We CT scanned the combination, modeled the cement with multiple material assignments in the TPS, designed plans with different field sizes and beam geometry for five photon modes, and measured the doses for all plans. All photon energies show significant error in calculated dose when the cement is modeled based on the CT number. Of the material assignments we evaluated, polytetrafluoroethylene (PTFE) showed the best overall agreement with measurement. Calculated and measured doses agree within 3.5% for a 340‐degree arc technique (which averages transmission and scatter effects) with the Acuros XB algorithm and PTFE as the assigned material. To confirm that PTFE is a reasonable substitute for kyphoplasty cement, we performed measurements in a slab phantom using rectangular inserts of cement and PTFE, showing average agreement of all photon modes within 2%. Based on these findings, we conclude that the PTFE material assignment provides acceptable dose calculation accuracy for the AAA and Acuros XB photon algorithms in the Eclipse TPS. We recommend that the cement be delineated as a structure and assigned the PTFE material for accurate dose calculation.
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Affiliation(s)
- Per H Halvorsen
- Department of Radiation Oncology, Lahey Hospital and Medical Center, Beth Israel Lahey Health, Burlington, MA, USA
| | - Navneeth Hariharan
- Department of Radiation Oncology, Lahey Hospital and Medical Center, Beth Israel Lahey Health, Burlington, MA, USA
| | - Zackary T Morelli
- Department of Radiation Oncology, Lahey Hospital and Medical Center, Beth Israel Lahey Health, Burlington, MA, USA
| | - Ileana N Iftimia
- Department of Radiation Oncology, Lahey Hospital and Medical Center, Beth Israel Lahey Health, Burlington, MA, USA
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15
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Bhushan M, Tripathi D, Yadav G, Kumar L, Chowdhary RL, Pahuja AK, Suresh T, Shukla SK, Mitra S. Feasibility of Monte-Carlo algorithm in comparison with collapse-cone dose calculation algorithm of a commercial treatment planning system in the presence of high-density metallic implant: a dosimetric study. J Egypt Natl Canc Inst 2021; 33:2. [PMID: 33415487 DOI: 10.1186/s43046-020-00057-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 12/20/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The number of people with implanted hip prosthesis has grown worldwide. For radiotherapy planning of patients with hip implants, few main challenges are encountered. The aim of the present study was to evaluate the feasibility of different planning algorithms in the presence of high-density metallic implant in the treatment of patients with carcinoma cervix. RESULTS It was found that D98% were 44.49 ± 0.11, 44.51 ± 0.13, 44.39 ± 0.22, and 44.45 ± 0.16 Gy for 4FMC6MV (4-field technique calculated with Monte-Carlo algorithm and 6 MV photon energy), 4FMC6MV_WP (4-field technique calculated with Monte-Carlo algorithm and 6 MV photon energy without prosthesis), 4FCC6MV (4-field technique calculated with collapse-cone-convolution algorithm and 6 MV photon energy), and 4FCC6MV_WP (4-field technique calculated with collapse-cone-convolution algorithm and 6 MV photon energy without prosthesis) respectively. Similarly, D2% were 49.40 ± 0.84, 49.05 ± 0.76, 48.97 ± 0.91, and 48.57 ± 0.85 Gray (Gy) for 4FMC6MV, 4FMC6MV_WP, 4FCC6MV, and 4FCC6MV_WP respectively. The present study has not suggested any major difference between the Monte-Carlo (MC) and collapse-cone-convolution (CCC) calculation algorithm in the presence of high-Z metallic implants. Volume of bowel receiving 15 Gy dose has shown a significant difference with prosthesis cases. This study investigates that hip prosthesis creates considerable changes in the treatment planning of cervical malignancies. CONCLUSION CCC algorithm is in good agreement with MC calculation algorithm in the presence of high-density metallic implants in terms of target coverage and avoidance organ sparing except few parameters.
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Affiliation(s)
- Manindra Bhushan
- Division of Medical Physics & Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, Sector-5, Rohini, New Delhi, 110085, India. .,Amity School of Applied Sciences, Amity University (AUUP), Noida, India.
| | - Deepak Tripathi
- Amity School of Applied Sciences, Amity University (AUUP), Noida, India
| | - Girigesh Yadav
- Division of Medical Physics & Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, Sector-5, Rohini, New Delhi, 110085, India
| | - Lalit Kumar
- Division of Medical Physics & Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, Sector-5, Rohini, New Delhi, 110085, India.,Dr. APJ Abdul Kalam Technical University, Lucknow, UP, India
| | - Rahul Lal Chowdhary
- Division of Medical Physics & Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, Sector-5, Rohini, New Delhi, 110085, India
| | - Anjali K Pahuja
- Division of Medical Physics & Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, Sector-5, Rohini, New Delhi, 110085, India
| | - Tamilarasu Suresh
- Division of Medical Physics & Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, Sector-5, Rohini, New Delhi, 110085, India
| | - Sushil Kumar Shukla
- Division of Medical Physics & Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, Sector-5, Rohini, New Delhi, 110085, India
| | - Swarupa Mitra
- Division of Medical Physics & Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, Sector-5, Rohini, New Delhi, 110085, India
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16
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The robustness of prostate radiotherapy for patients with hip prosthesis. Med Dosim 2020; 46:212-218. [PMID: 33349518 DOI: 10.1016/j.meddos.2020.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 11/30/2020] [Indexed: 11/23/2022]
Abstract
The aim of this study was to investigate prostate radiotherapy techniques for the patients with hip prosthesis in 4 different field setups. Volumetric Modulated Arc Therapy (VMAT) technique was used in 4 different cases: (1) using full VMAT arcs (VMAT_F); (2) same arcs as in case 1 but with avoidance sectors (VMAT_ASEC); (3) as case 2 but with the addition of a lateral static field through the prosthesis (VMAT_ASEC+STAT); (4) as in case 1 but with an automated structure avoidance option to avoid irradiation through the prosthesis (VMAT_ASTR). Fifteen previously treated prostate patients were retrospectively selected to this study. Treatment plans were created for all patients using all 4 techniques. The potential prosthesis misalignment in the treatment setup was modeled by moving the prosthesis 0.5, 1.0, and 1.5 cm ventrally and dorsally and recalculating the plans in each case. For VMAT_ASEC, the dose parameters for organs at risk were the highest and the dose coverage of the target volume was the poorest when compared to the other techniques. For VMAT_ASEC+STAT, the movement of the prosthesis changed the target dose distribution the most. VMAT_F and VMAT_ASTR fulfilled the planning criteria the best, even when the prosthesis was misaligned. VMAT_F radiated through the prosthesis more than VMAT_ASTR and increased the dose near the prosthesis surface when compared to VMAT_ASTR. VMAT_ASTR and VMAT_F were the most robust techniques for the patients with the hip prosthesis considering plan quality and the effect of positioning errors. The increased prosthesis surface dose with VMAT_F and possible dose calculation uncertainties favors the use of VMAT_ASTR.
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17
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Jayamani J, Osman ND, Tajuddin AA, Mohd Noor N, Abdul Aziz MZ. Dosimetric Comparison between Monaco TPS and EGSnrc Monte Carlo simulation on Titanium Rod in 12bit and 16bit Image Format. JOURNAL OF RADIATION RESEARCH AND APPLIED SCIENCES 2020. [DOI: 10.1080/16878507.2020.1754042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- J. Jayamani
- School of Health Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | - N. D. Osman
- Oncological and Radiological Sciences Cluster, Advanced Medical and Dental Insitute, Universiti Sains Malaysia, Kepala Batas, Pulau Pinang, Malaysia
| | - A. A. Tajuddin
- Oncological and Radiological Sciences Cluster, Advanced Medical and Dental Insitute, Universiti Sains Malaysia, Kepala Batas, Pulau Pinang, Malaysia
| | - N. Mohd Noor
- Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - M. Z. Abdul Aziz
- Oncological and Radiological Sciences Cluster, Advanced Medical and Dental Insitute, Universiti Sains Malaysia, Kepala Batas, Pulau Pinang, Malaysia
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Akdeniz Y, Yegingil I, Yegingil Z. Effects of metal implants and a metal artifact reduction tool on calculation accuracy of AAA and Acuros XB algorithms in small fields. Med Phys 2019; 46:5326-5335. [PMID: 31508819 DOI: 10.1002/mp.13819] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/28/2019] [Accepted: 09/04/2019] [Indexed: 11/05/2022] Open
Abstract
PURPOSE In this study, the dosimetric accuracy of analytical anisotropic algorithm (AAA) and Acuros XB (AXB) dose calculation algorithms (Varian Medical Systems, Palo Alto, CA) was investigated for small radiation fields incident on phantoms of various metals that include stainless steel grade 316L (SS316L) and titanium alloy grade 5 (Ti5) implants. In addition, the effects of using metal artifact reduction for orthopedic implants (O-MAR, Philips Healthcare, Cleveland, OH) were evaluated. METHODS The evaluations of AAA and AXB were performed by comparing the crossline profiles calculated by AAA and AXB with GafChromicTM EBT3 film measurements at the phantom-implant interfaces and in close vicinity of implant materials for small field sizes (1 × 1 cm2 , 2 × 2 cm2 , 3 × 3 cm2 , and 4 × 4 cm2 ) of a 6 MV flattening filter free photon beam. O-MAR corrected and uncorrected (UC) computed tomography (CT) images were used for dose calculations. The values of average and standard deviations (SD) of Hounsfield unit (HU) for selected regions of each case were evaluated. The differences in average dose percentages in defined regions were calculated to quantify the relative dosimetric changes between doses calculated on UC and O-MAR corrected CT images. RESULTS Compared to UC images, the values of SD were reduced, and the average HU became closer to its reference value in the O-MAR images. There was some discrepancy in average dose percentage differences between calculations using UC and O-MAR images at 1 cm above the SS316L implant (average dose percentage differences were AXB/UC = 5.9% and AXB/O-MAR = -1.2%; AAA/UC = 2.2%, and AAA/O-MAR = -0.8%). Neither AAA nor AXB algorithms predict increase in dose at upper phantom-implant interface (4.9%, 9.9%. 13.5%, and 13.8% for the fields from 1 × 1 cm2 to 4 × 4 cm2 , respectively). At the side of the SS316L implant (where dark streak artifacts exist), dose difference averages were estimated as - 1.1% and 22.3% when AXB/O-MAR and AXB/UC calculations are compared with EBT3 measurements, respectively. Dose predictions at 1 cm below the SS316L implant were underestimated by AXB/O-MAR (average -0.5%) and AXB/UC (average 2.0%). CONCLUSIONS The O-MAR tool was shown to have a favorable dosimetric effect or no effect on the calculations in the upper proximity of the implant materials. The dose differences between EBT3 film measurements and calculations at upper phantom-implant interfaces were smaller when they were calculated using O-MAR images. However, the dose differences increased when O-MAR corrected images were used for AAA calculations at lower phantom-implant interfaces. Use of O-MAR enabled closer agreement for the AXB algorithm, especially in the dark streak artifact regions. The O-MAR algorithm should be used when the dose is calculated with the AXB algorithm in cases of patients with the metal implants. The estimations using AAA and AXB algorithms, in phantom setups, with Ti5 implant material were found to be closer to the EBT3 film measurements, when compared with the same estimations using SS316L implant material.
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Affiliation(s)
- Yucel Akdeniz
- Department of Radiation Oncology, Acıbadem Adana Hospital, Seyhan, Adana, 01130, Turkey
| | - Ilhami Yegingil
- Department of Electrical and Electronics Engineering, Faculty of Engineering, Hasan Kalyoncu University, Gaziantep, Turkey
| | - Zehra Yegingil
- Department of Physics, Faculty of Science and Letters, Cukurova University, Saricam, Adana, 01330, Turkey
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Saadatmand P, Amouheidari A, Shanei A, Abedi I. Dose perturbation due to dental amalgam in the head and neck radiotherapy: A phantom study. Med Dosim 2019; 45:128-133. [PMID: 31537421 DOI: 10.1016/j.meddos.2019.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/22/2019] [Accepted: 08/13/2019] [Indexed: 12/14/2022]
Abstract
Dental amalgam, causes perturbation in photon dose distribution of head and neck (H&N) radiotherapy. The aim of this study was to evaluate the effects of dental amalgam on dose distribution of H&N radiotherapy and accuracy of dose calculations algorithm of commercial treatment planning system (TPS). In this study, the measurements were performed using a constructed H&N anthropomorphic. The sample of healthy teeth and teeth filled by amalgam inserted in the desired segment of the phantom in turn. After scanning and organs segmentation of phantom, intensity-modulated radiation therapy (IMRT) plan including 7 fields in the absence (plan 1) and presence (plan 2) of dental amalgam were created separately. Phantom was irradiated using 6 MV linear accelerator (SIMENS-ARTISTE, 5918). Assessment of the effects of dental amalgam on dose distribution and the accuracy of dose calculation algorithm of TPS was done by measurement and comparing of organ's received dose using thermoluminescent dosimeter (TLDs), placed on a phantom and TPS calculations. The scattering and attenuation due to the presence of dental amalgam led to an increase in parotid glands received dose (up to 24.38%) and a decrease in mean dose (up to -6.25%) PTV70. Results of this study revealed that discrepancies between the collapsed cone convolution (CCC) algorithm calculations Prowess Panther TPS and TLD measurements were -19.77% to 27.49% in presence of amalgam and -1.09% to 5.03% in presence of healthy teeth in phantoms. Attenuation and scattering due to amalgam in IMRT of H&N cancer may lead to a significant dose perturbation which is not predictable by dose calculation of TPS.
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Affiliation(s)
- Pegah Saadatmand
- Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | | | - Ahmad Shanei
- Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
| | - Iraj Abedi
- Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
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Thi Oanh L, Tai DT, Thi Hong Loan T, Minh TH, Van Minh T, Chow JCL. Dosimetric evaluation of lung treatment plans produced by the Prowess Panther system using Monte Carlo simulation. Biomed Phys Eng Express 2019. [DOI: 10.1088/2057-1976/ab367d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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[Radiotherapy after tumour prostheses-status, indication, coordination]. DER ORTHOPADE 2019; 48:605-609. [PMID: 30919000 DOI: 10.1007/s00132-019-03722-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Patients with complex tumour prostheses often require radiotherapy or radiochemotherapy. OBJECTIVES Possible tumour diagnoses, indications, planning and therapy procedures, and prognosis of radiotherapy in the context of an interdisciplinary treatment for bone sarcomas are reviewed, including interactions of metal prostheses with radiation and possible subsequent complications. METHODS Literature search, summary of personal experience. RESULTS Complex prosthetic procedures are usually applied to patients suffering from Ewing sarcoma or osteosarcoma. In patients with Ewing sarcoma, radiotherapy is an integral part of multimodal treatment, while in patients with osteosarcoma radiotherapy is indicated in special situations. Planning and implementation of radiotherapy treatment can be impaired by metal implants within the target volume (artefacts in the planning computerized tomography, interaction of metal with the therapeutic beam). However, it is-to our knowledge-a point of debate whether radiotherapy after implantation of a prosthesis could impair healing or prosthesis fixation to bone. The data available in the literature suggest that prostheses implanted after radiotherapy entail a higher rate of complications. Multidisciplinary treatment improves the prognosis for these patients markedly. CONCLUSIONS Patients with sarcomas of the bone undergoing interdisciplinary treatment consisting of surgery, radiotherapy and chemotherapy have a favourable prognosis and an acceptable functionality of the limb can be expected.
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Parenica HM, Mavroidis P, Jones W, Swanson G, Papanikolaou N, Stathakis S. VMAT Optimization and Dose Calculation in the Presence of Metallic Hip Prostheses. Technol Cancer Res Treat 2019; 18:1533033819892255. [PMID: 31789113 PMCID: PMC6887823 DOI: 10.1177/1533033819892255] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 09/26/2019] [Accepted: 11/08/2019] [Indexed: 12/25/2022] Open
Abstract
INTRODUCTION This research quantifies and compares the effect of hip prostheses on dose distributions calculated using collapsed cone convolution superposition and Monte Carlo (with and without correcting for the density of the implant and surrounding tissues). The use of full volumetric modulated arc therapy arcs versus volumetric modulated arc therapy arcs avoiding the hip implants (skip arcs) was also studied. MATERIALS AND METHODS Six prostate patients with hip prostheses were included in this study. The hip prostheses and the streaking artifacts on the computed tomography images were contoured by a single physician, and full volumetric modulated arc therapy arcs were created in the Pinnacle3 TPS. Copies of each plan were made, and the doses were recalculated with the densities of the prostheses and surrounding tissues overridden. The plans were then exported to Monaco and recalculated using a Monte Carlo dose calculation algorithm, with and without densities of the prosthesis and surrounding tissues overridden. RESULTS With density overrides, Pinnacle3 had a 4.4% error for ion chamber measurements. Monaco was within 0.2% of ion chamber measurement when density overrides were used. On average, when density overrides were used in Pinnacle3 for patient dose calculations, the planning target volume D95 value dropped from 99.3% to 82.7%. Monaco also showed decreased planning target volume coverage when plans were recalculated with correct density information. Full arc plans (with density overrides) for the patient with a bilateral prosthesis provided significant bladder sparing and some rectal sparing compared to skip arc plans. CONCLUSION When planning for prostate patients with hip prostheses, correct density information for implants and surrounding tissues should be used to optimize the plan and ensure optimal accuracy. If available, a Monte Carlo algorithm should be used as a second check. Full arcs could be used to spare dose to organs at risk, while maintaining adequate planning target volume coverage, when using a Monte Carlo dose calculation algorithm.
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Affiliation(s)
- Holly M. Parenica
- Department of Radiation Oncology, School of Medicine, The University of Texas Health Science Center at San Antonio, TX, USA
| | - Panayiotis Mavroidis
- Department of Radiation Oncology, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - William Jones
- Department of Radiation Oncology, South Texas Veterans Health Care System, San Antonio, TX, USA
| | - Gregory Swanson
- Department of Radiation Oncology, Baylor Scott & White Clinic-Temple, Temple, TX, USA
| | - Niko Papanikolaou
- Department of Radiation Oncology, School of Medicine, The University of Texas Health Science Center at San Antonio, TX, USA
| | - Sotirios Stathakis
- Department of Radiation Oncology, School of Medicine, The University of Texas Health Science Center at San Antonio, TX, USA
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